1. Field of the Invention
This invention relates generally to shipping and storage containers. More specifically, the invention relates to corrugated paperboard bulk bins configured to reduce sidewall bulge.
2. Prior Art
In the bulk handling of materials, e.g., processed poultry products, tomato paste, meat, fresh produce, etc., containers of relatively large-size are commonly used to transport and store the material. These containers must be capable of withstanding the weight of the contents, which can exceed two thousand pounds, as well as the rough handling to which they may be subjected. Further, they should be capable of being handled with mechanized equipment, which typically requires the container to be placed on a pallet. In the handling of certain poultry products, the pallet has dimensions of 48xc3x9740 inches, and the containers are sized to closely fit on the pallet.
A bulk bin commonly used for flowable products, e.g., ground-up poultry products, has a generally rectangular transverse cross-section, with the four corners mitered to produce an octagonal shape. This shape fits the 48xc3x9740 inch pallet typically used in the food industry. However, the resulting container has four relatively wide side walls or panels joined by four narrow diagonal panels. When a flowable product is loaded into the bin, the wide panels tend to buckle or bulge outwardly in the middle. The added package width caused by this buckling or bulging creates significant pallet overhang and an interference fit in warehouse storage racks and transportation trailers.
Accordingly, there is a need for a corrugated paperboard bulk bin which is configured to have reduced sidewall bulge when loaded with product, and which fits a standard 48xc3x9740 inch pallet.
The present invention comprises a bulk bin which is strong and durable, and which is configured to have less sidewall bulge than conventional bins when loaded with product.
In particular, the bin of the invention is made of corrugated paperboard and has an octagonal shape with opposed pairs of parallel side and end walls and diagonal corner panels. The diagonal corner panels are increased in width relative to conventional octagonal bins, whereby the diagonal corner panels have the same width as the end walls, thus reducing the width of the end walls as well as the width of the side walls. This relationship more evenly distributes the load, and reduces scoreline pressure, resulting in fewer failures and reduced sidewall bulge when the bin is loaded with product, especially flowable product. This eliminates problems of overhang and interference in warehouse storage racks and transportation trailers.
The bin of the invention has adequate strength to withstand the weight of the contents, and is configured so that it is capable of being palletized on conventional pallets so that it can be efficiently handled with mechanized equipment. The bin can be collapsed for compact storage, and has a locking bottom flap construction that is quick and easy to set up and is durable even when subjected to rough handling. A flexible liner or bag is generally placed in the bin when flowable materials are to be loaded into it.
In a specific example of an octagonal bulk bin incorporating the foregoing inventive feature, the width of the diagonal corner panels is increased by approximately 25%, or from 12xc2xc inches to 15xc2xd inches, and the width of the end walls is reduced by approximately 25%, or from 20xe2x85x9c inches to 15xc2xd inches, and the width of the side walls is reduced by approximately 20%, or from 28xe2x85x9c inches to 23xc2xd inches. Stated differently, the bin of the invention is a slightly elongated equilateral octagon, with the end walls and diagonal corner panels each having a width that is approximately two-thirds the width of the side walls. The distance or spacing between the opposed end walls and between the opposed side walls preferably remains the same as in a conventional octagonal bulk bin, whereby the bin of the invention will fit the pallets that are conventionally used. To maintain the volume the same as a conventional bin, the height of the bin of the invention may be increased by about 5%.
Further, strategically located crease lines may be placed in the sidewalls to cause buckling to occur in predetermined positions and patterns, further reducing the extent of bulge of the sidewalls should they buckle under pressure from the contents of the bin.
The invention is applicable to octagonal bulk bins regardless of the type of bottom flap construction used, but in a specific example of the invention, opposed pairs of major and minor bottom flaps are foldably joined along scorelines at one edge to respective pairs of opposed side and end walls, and have opposite free edges. The locking bottom flap construction includes cut-outs in the major flaps, and tabs on the free edge of each of the minor flaps. When the flaps are folded inwardly toward one another to close the bottom of the box, the tabs engage in the openings in the major flaps to lock the flaps in their inwardly folded position. It should be understood that this bottom flap construction does not form a part of the present invention, and other bottom closure designs can be used.
The bulk bin of the invention also may incorporate reinforcing straps in its sidewalls. In one specific example of the invention, these straps are tapes incorporated into the corrugated material. They may be spaced more closely together toward the bottom of the bin, or spaced uniformly along its height.
Although the preferred embodiment is an octagonal or eight-sided box, it should be understood that the invention may be adapted to other polygonal shapes, such as a ten-sided box, for example. Additionally, all the sides could be made equal in width, or the widths of some sides could vary plus or minus five percent from the width of other sides. Further, the box of the invention may comprise any suitable flute construction, including AA, CA, BC, etc., depending upon the desired properties. Moreover, a moisture resistant adhesive may be used in the manufacture of the box, which may additionally be treated with a suitable commercially available moisture resistant material.